<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
	input {
		border: 0;
	}
	.user {
		border-width: 1px;
		border-color: pink;
		border-style: solid;
	}
	.nc {
		border-top-width: 1px;
		border-top-color: hotpink; 
		border-top-style: solid;
		border-bottom-width: 1px;
		border-bottom-color: hotpink; 
		border-bottom-style: solid;
	}
	.email {
		border-top: 1px solid red;
		border-bottom: 1px solid green;
	}
	.tel {
		border: 1px solid skyblue;
	}
	</style>
	
</head>
<body>
	用户名: <input type="text" class="user" /> <br><br>
	昵  称: <input type="text" class="nc" /> <br><br>
	邮  箱: <input type="email" class="email" /> <br><br>
	手  机: <input type="tel" class="tel"> <br><br>
</body>
</html>